Guard interval-based waveform with data part and tail part

ABSTRACT

Disclosed are techniques for wireless communication. In an aspect, a wireless device maps data, a unique word (UW) sequence, and a suppression signal to a set of reserved time-domain resources based on a time-domain resource mapping and reservation rule to produce DFT input data. DFT processing is performed on the DFT input data to produce IFFT input data. IFFT processing is performed on the IFFT input data to produce the GI-based waveform with a data part (e.g., non-zero part) and a tail part (e.g., zero tail part). The wireless device may further transmit the GI-based waveform.

BACKGROUND OF THE DISCLOSURE 1. Field of the Disclosure

Aspects of the disclosure relate generally to wireless communications.

2. Description of the Related Art

Wireless communication systems have developed through various generations, including a first-generation analog wireless phone service (1G), a second-generation (2G) digital wireless phone service (including interim 2.5G and 2.75G networks), a third-generation (3G) high speed data, Internet-capable wireless service and a fourth-generation (4G) service (e.g., Long Term Evolution (LTE) or WiMax). There are presently many different types of wireless communication systems in use, including cellular and personal communications service (PCS) systems. Examples of known cellular systems include the cellular analog advanced mobile phone system (AMPS), and digital cellular systems based on code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), the Global System for Mobile communications (GSM), etc.

A fifth generation (5G) wireless standard, referred to as New Radio (NR), calls for higher data transfer speeds, greater numbers of connections, and better coverage, among other improvements. The 5G standard, according to the Next Generation Mobile Networks Alliance, is designed to provide data rates of several tens of megabits per second to each of tens of thousands of users, with 1 gigabit per second to tens of workers on an office floor. Several hundreds of thousands of simultaneous connections should be supported in order to support large sensor deployments. Consequently, the spectral efficiency of 5G mobile communications should be significantly enhanced compared to the current 4G standard. Furthermore, signaling efficiencies should be enhanced and latency should be substantially reduced compared to current standards.

SUMMARY

The following presents a simplified summary relating to one or more aspects disclosed herein. Thus, the following summary should not be considered an extensive overview relating to all contemplated aspects, nor should the following summary be considered to identify key or critical elements relating to all contemplated aspects or to delineate the scope associated with any particular aspect. Accordingly, the following summary has the sole purpose to present certain concepts relating to one or more aspects relating to the mechanisms disclosed herein in a simplified form to precede the detailed description presented below.

In an aspect, a method of operating a wireless device includes obtaining data for transmission in a guard interval (GI)-based waveform with a data part and a tail part; obtaining a unique word (UW) sequence for the tail part; and obtaining a suppression signal with filter coefficients configured to suppress leakage from the data part to the tail part; mapping the data, the UW sequence, and the suppression signal to a set of reserved time-domain resources based on a time-domain resource mapping and reservation rule to produce Discrete Fourier Transform (DFT) input data; performing DFT processing on the DFT input data to produce Inverse Fast Fourier Transform (IFFT) input data; performing IFFT processing on the IFFT input data to produce the GI-based waveform with the data part and the tail part; and transmitting the GI-based waveform.

In some aspects, the filter coefficients are defined before the mapping, or some or all of the filter coefficients are defined as a function of the mapping.

In some aspects, the tail part corresponds to a zero tail part.

In some aspects, the filter coefficients are predetermined based on the time-domain resource mapping and reservation rule, an oversampling ratio and a starting time-domain resource among the set of time-domain resources.

In some aspects, an initial set of filter coefficients is predetermined based on the time-domain resource mapping and reservation rule and an oversampling ratio, and the filter coefficients are dynamically derived based on the initial set of filter coefficients and a starting time-domain resource among the set of time-domain resources.

In some aspects, the method includes storing predefined filter coefficients for a first subset of time-domain resources, wherein a second subset of time-domain resources is associated with dynamic derivation of filter coefficients.

In some aspects, the method includes obtaining a set of candidate filter coefficients; and setting any candidate filter coefficient in the set of candidate filter coefficients that is below a threshold to zero to produce the filter coefficients for the suppression signal.

In some aspects, each filter coefficient of the filter coefficients of the suppression signal is defined based on a set of values associated with a set of adjacent neighbors.

In some aspects, each filter coefficient of the filter coefficients of the suppression signal is defined based on an average of the set of values associated with the set of adjacent neighbors.

In an aspect, a wireless device includes a memory; at least one transceiver; and at least one processor communicatively coupled to the memory and the at least one transceiver, the at least one processor configured to: obtain data for transmission in a guard interval (GI)-based waveform with a data part and a tail part; obtain a unique word (UW) sequence for the tail part; and obtain a suppression signal with filter coefficients configured to suppress leakage from the data part to the tail part; map the data, the UW sequence, and the suppression signal to a set of reserved time-domain resources based on a time-domain resource mapping and reservation rule to produce Discrete Fourier Transform (DFT) input data; perform DFT processing on the DFT input data to produce Inverse Fast Fourier Transform (IFFT) input data; perform IFFT processing on the IFFT input data to produce the GI-based waveform with the data part and the tail part; and transmit, via the at least one transceiver, the GI-based waveform.

In some aspects, the filter coefficients are defined before the mapping, or some or all of the filter coefficients are defined as a function of the mapping.

In some aspects, the tail part corresponds to a zero tail part.

In some aspects, the filter coefficients are predetermined based on the time-domain resource mapping and reservation rule, an oversampling ratio and a starting time-domain resource among the set of time-domain resources.

In some aspects, an initial set of filter coefficients is predetermined based on the time-domain resource mapping and reservation rule and an oversampling ratio, and the filter coefficients are dynamically derived based on the initial set of filter coefficients and a starting time-domain resource among the set of time-domain resources.

In some aspects, the at least one processor is further configured to: store predefined filter coefficients for a first subset of time-domain resources, wherein a second subset of time-domain resources is associated with dynamic derivation of filter coefficients.

In some aspects, the at least one processor is further configured to: obtain a set of candidate filter coefficients; and set any candidate filter coefficient in the set of candidate filter coefficients that is below a threshold to zero to produce the filter coefficients for the suppression signal.

In some aspects, each filter coefficient of the filter coefficients of the suppression signal is defined based on a set of values associated with a set of adjacent neighbors.

In some aspects, each filter coefficient of the filter coefficients of the suppression signal is defined based on an average of the set of values associated with the set of adjacent neighbors.

In an aspect, a wireless device includes means for obtaining data for transmission in a guard interval (GI)-based waveform with a data part and a tail part; means for obtaining a unique word (UW) sequence for the tail part; and means for obtaining a suppression signal with filter coefficients configured to suppress leakage from the data part to the tail part; means for mapping the data, the UW sequence, and the suppression signal to a set of reserved time-domain resources based on a time-domain resource mapping and reservation rule to produce Discrete Fourier Transform (DFT) input data; means for performing DFT processing on the DFT input data to produce Inverse Fast Fourier Transform (IFFT) input data; means for performing IFFT processing on the IFFT input data to produce the GI-based waveform with the data part and the tail part; and means for transmitting the GI-based waveform.

In some aspects, the filter coefficients are defined before the mapping, or some or all of the filter coefficients are defined as a function of the mapping.

In some aspects, the tail part corresponds to a zero tail part.

In some aspects, the filter coefficients are predetermined based on the time-domain resource mapping and reservation rule, an oversampling ratio and a starting time-domain resource among the set of time-domain resources.

In some aspects, an initial set of filter coefficients is predetermined based on the time-domain resource mapping and reservation rule and an oversampling ratio, and the filter coefficients are dynamically derived based on the initial set of filter coefficients and a starting time-domain resource among the set of time-domain resources.

In some aspects, the method includes means for storing predefined filter coefficients for a first subset of time-domain resources, wherein a second subset of time-domain resources is associated with dynamic derivation of filter coefficients.

In some aspects, the method includes means for obtaining a set of candidate filter coefficients; and means for setting any candidate filter coefficient in the set of candidate filter coefficients that is below a threshold to zero to produce the filter coefficients for the suppression signal.

In some aspects, each filter coefficient of the filter coefficients of the suppression signal is defined based on a set of values associated with a set of adjacent neighbors.

In some aspects, each filter coefficient of the filter coefficients of the suppression signal is defined based on an average of the set of values associated with the set of adjacent neighbors.

In an aspect, a non-transitory computer-readable medium storing computer-executable instructions that, when executed by a wireless device, cause the wireless device to: obtain data for transmission in a guard interval (GI)-based waveform with a data part and a tail part; obtain a unique word (UW) sequence for the tail part; and obtain a suppression signal with filter coefficients configured to suppress leakage from the data part to the tail part; map the data, the UW sequence, and the suppression signal to a set of reserved time-domain resources based on a time-domain resource mapping and reservation rule to produce Discrete Fourier Transform (DFT) input data; perform DFT processing on the DFT input data to produce Inverse Fast Fourier Transform (IFFT) input data; perform IFFT processing on the IFFT input data to produce the GI-based waveform with the data part and the tail part; and transmit the GI-based waveform.

In some aspects, the filter coefficients are defined before the mapping, or some or all of the filter coefficients are defined as a function of the mapping.

In some aspects, the tail part corresponds to a zero tail part.

In some aspects, the filter coefficients are predetermined based on the time-domain resource mapping and reservation rule, an oversampling ratio and a starting time-domain resource among the set of time-domain resources.

In some aspects, an initial set of filter coefficients is predetermined based on the time-domain resource mapping and reservation rule and an oversampling ratio, and the filter coefficients are dynamically derived based on the initial set of filter coefficients and a starting time-domain resource among the set of time-domain resources.

In some aspects, computer-executable instructions that, when executed by the wireless device, cause the wireless device to:

In some aspects, computer-executable instructions that, when executed by the wireless device, cause the wireless device to:

In some aspects, each filter coefficient of the filter coefficients of the suppression signal is defined based on a set of values associated with a set of adjacent neighbors.

In some aspects, each filter coefficient of the filter coefficients of the suppression signal is defined based on an average of the set of values associated with the set of adjacent neighbors.

Other objects and advantages associated with the aspects disclosed herein will be apparent to those skilled in the art based on the accompanying drawings and detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are presented to aid in the description of various aspects of the disclosure and are provided solely for illustration of the aspects and not limitation thereof.

FIG. 1 illustrates an example wireless communications system, according to aspects of the disclosure.

FIGS. 2A and 2B illustrate example wireless network structures, according to aspects of the disclosure.

FIGS. 3A, 3B, and 3C are simplified block diagrams of several sample aspects of components that may be employed in a user equipment (UE), a base station, and a network entity, respectively, and configured to support communications as taught herein.

FIG. 4 depicts waveform configurations in accordance with aspects of the disclosure.

FIG. 5 depicts slot configurations in accordance with aspects of the disclosure.

FIG. 6 illustrates a GI-based waveform generation procedure in accordance with an aspect of the disclosure.

FIG. 7 illustrates an exemplary process of wireless communication, according to aspects of the disclosure.

FIG. 8 illustrates an example implementation of the process of FIG. 7 in accordance with aspects of the disclosure.

DETAILED DESCRIPTION

Aspects of the disclosure are provided in the following description and related drawings directed to various examples provided for illustration purposes. Alternate aspects may be devised without departing from the scope of the disclosure. Additionally, well-known elements of the disclosure will not be described in detail or will be omitted so as not to obscure the relevant details of the disclosure.

The words “exemplary” and/or “example” are used herein to mean “serving as an example, instance, or illustration.” Any aspect described herein as “exemplary” and/or “example” is not necessarily to be construed as preferred or advantageous over other aspects. Likewise, the term “aspects of the disclosure” does not require that all aspects of the disclosure include the discussed feature, advantage or mode of operation.

Those of skill in the art will appreciate that the information and signals described below may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the description below may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof, depending in part on the particular application, in part on the desired design, in part on the corresponding technology, etc.

Further, many aspects are described in terms of sequences of actions to be performed by, for example, elements of a computing device. It will be recognized that various actions described herein can be performed by specific circuits (e.g., application specific integrated circuits (ASICs)), by program instructions being executed by one or more processors, or by a combination of both. Additionally, the sequence(s) of actions described herein can be considered to be embodied entirely within any form of non-transitory computer-readable storage medium having stored therein a corresponding set of computer instructions that, upon execution, would cause or instruct an associated processor of a device to perform the functionality described herein. Thus, the various aspects of the disclosure may be embodied in a number of different forms, all of which have been contemplated to be within the scope of the claimed subject matter. In addition, for each of the aspects described herein, the corresponding form of any such aspects may be described herein as, for example, “logic configured to” perform the described action.

As used herein, the terms “user equipment” (UE) and “base station” are not intended to be specific or otherwise limited to any particular radio access technology (RAT), unless otherwise noted. In general, a UE may be any wireless communication device (e.g., a mobile phone, router, tablet computer, laptop computer, consumer asset locating device, wearable (e.g., smartwatch, glasses, augmented reality (AR)/virtual reality (VR) headset, etc.), vehicle (e.g., automobile, motorcycle, bicycle, etc.), Internet of Things (IoT) device, etc.) used by a user to communicate over a wireless communications network. A UE may be mobile or may (e.g., at certain times) be stationary, and may communicate with a radio access network (RAN). As used herein, the term “UE” may be referred to interchangeably as an “access terminal” or “AT,” a “client device,” a “wireless device,” a “subscriber device,” a “subscriber terminal,” a “subscriber station,” a “user terminal” or “UT,” a “mobile device,” a “mobile terminal,” a “mobile station,” or variations thereof. Generally, UEs can communicate with a core network via a RAN, and through the core network the UEs can be connected with external networks such as the Internet and with other UEs. Of course, other mechanisms of connecting to the core network and/or the Internet are also possible for the UEs, such as over wired access networks, wireless local area network (WLAN) networks (e.g., based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 specification, etc.) and so on.

A base station may operate according to one of several RATs in communication with UEs depending on the network in which it is deployed, and may be alternatively referred to as an access point (AP), a network node, a NodeB, an evolved NodeB (eNB), a next generation eNB (ng-eNB), a New Radio (NR) Node B (also referred to as a gNB or gNodeB), etc. A base station may be used primarily to support wireless access by UEs, including supporting data, voice, and/or signaling connections for the supported UEs. In some systems a base station may provide purely edge node signaling functions while in other systems it may provide additional control and/or network management functions. A communication link through which UEs can send signals to a base station is called an uplink (UL) channel (e.g., a reverse traffic channel, a reverse control channel, an access channel, etc.). A communication link through which the base station can send signals to UEs is called a downlink (DL) or forward link channel (e.g., a paging channel, a control channel, a broadcast channel, a forward traffic channel, etc.). As used herein the term traffic channel (TCH) can refer to either an uplink/reverse or downlink/forward traffic channel.

The term “base station” may refer to a single physical transmission-reception point (TRP) or to multiple physical TRPs that may or may not be co-located. For example, where the term “base station” refers to a single physical TRP, the physical TRP may be an antenna of the base station corresponding to a cell (or several cell sectors) of the base station. Where the term “base station” refers to multiple co-located physical TRPs, the physical TRPs may be an array of antennas (e.g., as in a multiple-input multiple-output (MIMO) system or where the base station employs beamforming) of the base station. Where the term “base station” refers to multiple non-co-located physical TRPs, the physical TRPs may be a distributed antenna system (DAS) (a network of spatially separated antennas connected to a common source via a transport medium) or a remote radio head (RRH) (a remote base station connected to a serving base station). Alternatively, the non-co-located physical TRPs may be the serving base station receiving the measurement report from the UE and a neighbor base station whose reference radio frequency (RF) signals the UE is measuring. Because a TRP is the point from which a base station transmits and receives wireless signals, as used herein, references to transmission from or reception at a base station are to be understood as referring to a particular TRP of the base station.

In some implementations that support positioning of UEs, a base station may not support wireless access by UEs (e.g., may not support data, voice, and/or signaling connections for UEs), but may instead transmit reference signals to UEs to be measured by the UEs, and/or may receive and measure signals transmitted by the UEs. Such a base station may be referred to as a positioning beacon (e.g., when transmitting signals to UEs) and/or as a location measurement unit (e.g., when receiving and measuring signals from UEs).

An “RF signal” comprises an electromagnetic wave of a given frequency that transports information through the space between a transmitter and a receiver. As used herein, a transmitter may transmit a single “RF signal” or multiple “RF signals” to a receiver. However, the receiver may receive multiple “RF signals” corresponding to each transmitted RF signal due to the propagation characteristics of RF signals through multipath channels. The same transmitted RF signal on different paths between the transmitter and receiver may be referred to as a “multipath” RF signal. As used herein, an RF signal may also be referred to as a “wireless signal” or simply a “signal” where it is clear from the context that the term “signal” refers to a wireless signal or an RF signal.

FIG. 1 illustrates an example wireless communications system 100, according to aspects of the disclosure. The wireless communications system 100 (which may also be referred to as a wireless wide area network (WWAN)) may include various base stations 102 (labeled “BS”) and various UEs 104. The base stations 102 may include macro cell base stations (high power cellular base stations) and/or small cell base stations (low power cellular base stations). In an aspect, the macro cell base stations may include eNBs and/or ng-eNBs where the wireless communications system 100 corresponds to an LTE network, or gNBs where the wireless communications system 100 corresponds to a NR network, or a combination of both, and the small cell base stations may include femtocells, picocells, microcells, etc.

The base stations 102 may collectively form a RAN and interface with a core network 170 (e.g., an evolved packet core (EPC) or a 5G core (5GC)) through backhaul links 122, and through the core network 170 to one or more location servers 172 (e.g., a location management function (LMF) or a secure user plane location (SUPL) location platform (SLP)). The location server(s) 172 may be part of core network 170 or may be external to core network 170. A location server 172 may be integrated with a base station 102. A UE 104 may communicate with a location server 172 directly or indirectly. For example, a UE 104 may communicate with a location server 172 via the base station 102 that is currently serving that UE 104. A UE 104 may also communicate with a location server 172 through another path, such as via an application server (not shown), via another network, such as via a wireless local area network (WLAN) access point (AP) (e.g., AP 150 described below), and so on. For signaling purposes, communication between a UE 104 and a location server 172 may be represented as an indirect connection (e.g., through the core network 170, etc.) or a direct connection (e.g., as shown via direct connection 128), with the intervening nodes (if any) omitted from a signaling diagram for clarity.

In addition to other functions, the base stations 102 may perform functions that relate to one or more of transferring user data, radio channel ciphering and deciphering, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection setup and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, RAN sharing, multimedia broadcast multicast service (MBMS), subscriber and equipment trace, RAN information management (RIM), paging, positioning, and delivery of warning messages. The base stations 102 may communicate with each other directly or indirectly (e.g., through the EPC/5GC) over backhaul links 134, which may be wired or wireless.

The base stations 102 may wirelessly communicate with the UEs 104. Each of the base stations 102 may provide communication coverage for a respective geographic coverage area 110. In an aspect, one or more cells may be supported by a base station 102 in each geographic coverage area 110. A “cell” is a logical communication entity used for communication with a base station (e.g., over some frequency resource, referred to as a carrier frequency, component carrier, carrier, band, or the like), and may be associated with an identifier (e.g., a physical cell identifier (PCI), an enhanced cell identifier (ECI), a virtual cell identifier (VCI), a cell global identifier (CGI), etc.) for distinguishing cells operating via the same or a different carrier frequency. In some cases, different cells may be configured according to different protocol types (e.g., machine-type communication (MTC), narrowband IoT (NB-IoT), enhanced mobile broadband (eMBB), or others) that may provide access for different types of UEs. Because a cell is supported by a specific base station, the term “cell” may refer to either or both of the logical communication entity and the base station that supports it, depending on the context. In addition, because a TRP is typically the physical transmission point of a cell, the terms “cell” and “TRP” may be used interchangeably. In some cases, the term “cell” may also refer to a geographic coverage area of a base station (e.g., a sector), insofar as a carrier frequency can be detected and used for communication within some portion of geographic coverage areas 110.

While neighboring macro cell base station 102 geographic coverage areas 110 may partially overlap (e.g., in a handover region), some of the geographic coverage areas 110 may be substantially overlapped by a larger geographic coverage area 110. For example, a small cell base station 102′ (labeled “SC” for “small cell”) may have a geographic coverage area 110′ that substantially overlaps with the geographic coverage area 110 of one or more macro cell base stations 102. A network that includes both small cell and macro cell base stations may be known as a heterogeneous network. A heterogeneous network may also include home eNBs (HeNBs), which may provide service to a restricted group known as a closed subscriber group (CSG).

The communication links 120 between the base stations 102 and the UEs 104 may include uplink (also referred to as reverse link) transmissions from a UE 104 to a base station 102 and/or downlink (DL) (also referred to as forward link) transmissions from a base station 102 to a UE 104. The communication links 120 may use MIMO antenna technology, including spatial multiplexing, beamforming, and/or transmit diversity. The communication links 120 may be through one or more carrier frequencies. Allocation of carriers may be asymmetric with respect to downlink and uplink (e.g., more or less carriers may be allocated for downlink than for uplink).

The wireless communications system 100 may further include a wireless local area network (WLAN) access point (AP) 150 in communication with WLAN stations (STAs) 152 via communication links 154 in an unlicensed frequency spectrum (e.g., 5 GHz). When communicating in an unlicensed frequency spectrum, the WLAN STAs 152 and/or the WLAN AP 150 may perform a clear channel assessment (CCA) or listen before talk (LBT) procedure prior to communicating in order to determine whether the channel is available.

The small cell base station 102′ may operate in a licensed and/or an unlicensed frequency spectrum. When operating in an unlicensed frequency spectrum, the small cell base station 102′ may employ LTE or NR technology and use the same 5 GHz unlicensed frequency spectrum as used by the WLAN AP 150. The small cell base station 102′, employing LTE/5G in an unlicensed frequency spectrum, may boost coverage to and/or increase capacity of the access network. NR in unlicensed spectrum may be referred to as NR-U. LTE in an unlicensed spectrum may be referred to as LTE-U, licensed assisted access (LAA), or MulteFire.

The wireless communications system 100 may further include a millimeter wave (mmW) base station 180 that may operate in mmW frequencies and/or near mmW frequencies in communication with a UE 182. Extremely high frequency (EHF) is part of the RF in the electromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz and a wavelength between 1 millimeter and 10 millimeters. Radio waves in this band may be referred to as a millimeter wave. Near mmW may extend down to a frequency of 3 GHz with a wavelength of 100 millimeters. The super high frequency (SHF) band extends between 3 GHz and 30 GHz, also referred to as centimeter wave. Communications using the mmW/near mmW radio frequency band have high path loss and a relatively short range. The mmW base station 180 and the UE 182 may utilize beamforming (transmit and/or receive) over a mmW communication link 184 to compensate for the extremely high path loss and short range. Further, it will be appreciated that in alternative configurations, one or more base stations 102 may also transmit using mmW or near mmW and beamforming. Accordingly, it will be appreciated that the foregoing illustrations are merely examples and should not be construed to limit the various aspects disclosed herein.

Transmit beamforming is a technique for focusing an RF signal in a specific direction. Traditionally, when a network node (e.g., a base station) broadcasts an RF signal, it broadcasts the signal in all directions (omni-directionally). With transmit beamforming, the network node determines where a given target device (e.g., a UE) is located (relative to the transmitting network node) and projects a stronger downlink RF signal in that specific direction, thereby providing a faster (in terms of data rate) and stronger RF signal for the receiving device(s). To change the directionality of the RF signal when transmitting, a network node can control the phase and relative amplitude of the RF signal at each of the one or more transmitters that are broadcasting the RF signal. For example, a network node may use an array of antennas (referred to as a “phased array” or an “antenna array”) that creates a beam of RF waves that can be “steered” to point in different directions, without actually moving the antennas. Specifically, the RF current from the transmitter is fed to the individual antennas with the correct phase relationship so that the radio waves from the separate antennas add together to increase the radiation in a desired direction, while cancelling to suppress radiation in undesired directions.

Transmit beams may be quasi-co-located, meaning that they appear to the receiver (e.g., a UE) as having the same parameters, regardless of whether or not the transmitting antennas of the network node themselves are physically co-located. In NR, there are four types of quasi-co-location (QCL) relations. Specifically, a QCL relation of a given type means that certain parameters about a second reference RF signal on a second beam can be derived from information about a source reference RF signal on a source beam. Thus, if the source reference RF signal is QCL Type A, the receiver can use the source reference RF signal to estimate the Doppler shift, Doppler spread, average delay, and delay spread of a second reference RF signal transmitted on the same channel. If the source reference RF signal is QCL Type B, the receiver can use the source reference RF signal to estimate the Doppler shift and Doppler spread of a second reference RF signal transmitted on the same channel. If the source reference RF signal is QCL Type C, the receiver can use the source reference RF signal to estimate the Doppler shift and average delay of a second reference RF signal transmitted on the same channel. If the source reference RF signal is QCL Type D, the receiver can use the source reference RF signal to estimate the spatial receive parameter of a second reference RF signal transmitted on the same channel.

In receive beamforming, the receiver uses a receive beam to amplify RF signals detected on a given channel. For example, the receiver can increase the gain setting and/or adjust the phase setting of an array of antennas in a particular direction to amplify (e.g., to increase the gain level of) the RF signals received from that direction. Thus, when a receiver is said to beamform in a certain direction, it means the beam gain in that direction is high relative to the beam gain along other directions, or the beam gain in that direction is the highest compared to the beam gain in that direction of all other receive beams available to the receiver. This results in a stronger received signal strength (e.g., reference signal received power (RSRP), reference signal received quality (RSRQ), signal-to-interference-plus-noise ratio (SINR), etc.) of the RF signals received from that direction.

Transmit and receive beams may be spatially related. A spatial relation means that parameters for a second beam (e.g., a transmit or receive beam) for a second reference signal can be derived from information about a first beam (e.g., a receive beam or a transmit beam) for a first reference signal. For example, a UE may use a particular receive beam to receive a reference downlink reference signal (e.g., synchronization signal block (SSB)) from a base station. The UE can then form a transmit beam for sending an uplink reference signal (e.g., sounding reference signal (SRS)) to that base station based on the parameters of the receive beam.

Note that a “downlink” beam may be either a transmit beam or a receive beam, depending on the entity forming it. For example, if a base station is forming the downlink beam to transmit a reference signal to a UE, the downlink beam is a transmit beam. If the UE is forming the downlink beam, however, it is a receive beam to receive the downlink reference signal. Similarly, an “uplink” beam may be either a transmit beam or a receive beam, depending on the entity forming it. For example, if a base station is forming the uplink beam, it is an uplink receive beam, and if a UE is forming the uplink beam, it is an uplink transmit beam.

The electromagnetic spectrum is often subdivided, based on frequency/wavelength, into various classes, bands, channels, etc. In 5G NR two initial operating bands have been identified as frequency range designations FR1 (410 MHz-7.125 GHz) and FR2 (24.25 GHz-52.6 GHz). It should be understood that although a portion of FR1 is greater than 6 GHz, FR1 is often referred to (interchangeably) as a “Sub-6 GHz” band in various documents and articles. A similar nomenclature issue sometimes occurs with regard to FR2, which is often referred to (interchangeably) as a “millimeter wave” band in documents and articles, despite being different from the extremely high frequency (EHF) band (30 GHz-300 GHz) which is identified by the International Telecommunications Union (ITU) as a “millimeter wave” band.

The frequencies between FR1 and FR2 are often referred to as mid-band frequencies. Recent 5G NR studies have identified an operating band for these mid-band frequencies as frequency range designation FR3 (7.125 GHz-24.25 GHz). Frequency bands falling within FR3 may inherit FR1 characteristics and/or FR2 characteristics, and thus may effectively extend features of FR1 and/or FR2 into mid-band frequencies. In addition, higher frequency bands are currently being explored to extend 5G NR operation beyond 52.6 GHz. For example, three higher operating bands have been identified as frequency range designations FR4a or FR4-1 (52.6 GHz-71 GHz), FR4 (52.6 GHz-114.25 GHz), and FR5 (114.25 GHz-300 GHz). Each of these higher frequency bands falls within the EHF band.

With the above aspects in mind, unless specifically stated otherwise, it should be understood that the term “sub-6 GHz” or the like if used herein may broadly represent frequencies that may be less than 6 GHz, may be within FR1, or may include mid-band frequencies. Further, unless specifically stated otherwise, it should be understood that the term “millimeter wave” or the like if used herein may broadly represent frequencies that may include mid-band frequencies, may be within FR2, FR4, FR4-a or FR4-1, and/or FR5, or may be within the EHF band.

In a multi-carrier system, such as 5G, one of the carrier frequencies is referred to as the “primary carrier” or “anchor carrier” or “primary serving cell” or “PCell,” and the remaining carrier frequencies are referred to as “secondary carriers” or “secondary serving cells” or “SCells.” In carrier aggregation, the anchor carrier is the carrier operating on the primary frequency (e.g., FR1) utilized by a UE 104/182 and the cell in which the UE 104/182 either performs the initial radio resource control (RRC) connection establishment procedure or initiates the RRC connection re-establishment procedure. The primary carrier carries all common and UE-specific control channels, and may be a carrier in a licensed frequency (however, this is not always the case). A secondary carrier is a carrier operating on a second frequency (e.g., FR2) that may be configured once the RRC connection is established between the UE 104 and the anchor carrier and that may be used to provide additional radio resources. In some cases, the secondary carrier may be a carrier in an unlicensed frequency. The secondary carrier may contain only necessary signaling information and signals, for example, those that are UE-specific may not be present in the secondary carrier, since both primary uplink and downlink carriers are typically UE-specific. This means that different UEs 104/182 in a cell may have different downlink primary carriers. The same is true for the uplink primary carriers. The network is able to change the primary carrier of any UE 104/182 at any time. This is done, for example, to balance the load on different carriers. Because a “serving cell” (whether a PCell or an SCell) corresponds to a carrier frequency/component carrier over which some base station is communicating, the term “cell,” “serving cell,” “component carrier,” “carrier frequency,” and the like can be used interchangeably.

For example, still referring to FIG. 1 , one of the frequencies utilized by the macro cell base stations 102 may be an anchor carrier (or “PCell”) and other frequencies utilized by the macro cell base stations 102 and/or the mmW base station 180 may be secondary carriers (“SCells”). The simultaneous transmission and/or reception of multiple carriers enables the UE 104/182 to significantly increase its data transmission and/or reception rates. For example, two 20 MHz aggregated carriers in a multi-carrier system would theoretically lead to a two-fold increase in data rate (i.e., 40 MHz), compared to that attained by a single 20 MHz carrier.

The wireless communications system 100 may further include a UE 164 that may communicate with a macro cell base station 102 over a communication link 120 and/or the mmW base station 180 over a mmW communication link 184. For example, the macro cell base station 102 may support a PCell and one or more SCells for the UE 164 and the mmW base station 180 may support one or more SCells for the UE 164.

In some cases, the UE 164 and the UE 182 may be capable of sidelink communication. Sidelink-capable UEs (SL-UEs) may communicate with base stations 102 over communication links 120 using the Uu interface (i.e., the air interface between a UE and a base station). SL-UEs (e.g., UE 164, UE 182) may also communicate directly with each other over a wireless sidelink 160 using the PC5 interface (i.e., the air interface between sidelink-capable UEs). A wireless sidelink (or just “sidelink”) is an adaptation of the core cellular (e.g., LTE, NR) standard that allows direct communication between two or more UEs without the communication needing to go through a base station. Sidelink communication may be unicast or multicast, and may be used for device-to-device (D2D) media-sharing, vehicle-to-vehicle (V2V) communication, vehicle-to-everything (V2X) communication (e.g., cellular V2X (cV2X) communication, enhanced V2X (eV2X) communication, etc.), emergency rescue applications, etc. One or more of a group of SL-UEs utilizing sidelink communications may be within the geographic coverage area 110 of a base station 102. Other SL-UEs in such a group may be outside the geographic coverage area 110 of a base station 102 or be otherwise unable to receive transmissions from a base station 102. In some cases, groups of SL-UEs communicating via sidelink communications may utilize a one-to-many (1:M) system in which each SL-UE transmits to every other SL-UE in the group. In some cases, a base station 102 facilitates the scheduling of resources for sidelink communications. In other cases, sidelink communications are carried out between SL-UEs without the involvement of a base station 102.

In an aspect, the sidelink 160 may operate over a wireless communication medium of interest, which may be shared with other wireless communications between other vehicles and/or infrastructure access points, as well as other RATs. A “medium” may be composed of one or more time, frequency, and/or space communication resources (e.g., encompassing one or more channels across one or more carriers) associated with wireless communication between one or more transmitter/receiver pairs. In an aspect, the medium of interest may correspond to at least a portion of an unlicensed frequency band shared among various RATs. Although different licensed frequency bands have been reserved for certain communication systems (e.g., by a government entity such as the Federal Communications Commission (FCC) in the United States), these systems, in particular those employing small cell access points, have recently extended operation into unlicensed frequency bands such as the Unlicensed National Information Infrastructure (U-MI) band used by wireless local area network (WLAN) technologies, most notably IEEE 802.11x WLAN technologies generally referred to as “Wi-Fi.” Example systems of this type include different variants of CDMA systems, TDMA systems, FDMA systems, orthogonal FDMA (OFDMA) systems, single-carrier FDMA (SC-FDMA) systems, and so on.

Note that although FIG. 1 only illustrates two of the UEs as SL-UEs (i.e., UEs 164 and 182), any of the illustrated UEs may be SL-UEs. Further, although only UE 182 was described as being capable of beamforming, any of the illustrated UEs, including UE 164, may be capable of beamforming. Where SL-UEs are capable of beamforming, they may beamform towards each other (i.e., towards other SL-UEs), towards other UEs (e.g., UEs 104), towards base stations (e.g., base stations 102, 180, small cell 102′, access point 150), etc. Thus, in some cases, UEs 164 and 182 may utilize beamforming over sidelink 160.

In the example of FIG. 1 , any of the illustrated UEs (shown in FIG. 1 as a single UE 104 for simplicity) may receive signals 124 from one or more Earth orbiting space vehicles (SVs) 112 (e.g., satellites). In an aspect, the SVs 112 may be part of a satellite positioning system that a UE 104 can use as an independent source of location information. A satellite positioning system typically includes a system of transmitters (e.g., SVs 112) positioned to enable receivers (e.g., UEs 104) to determine their location on or above the Earth based, at least in part, on positioning signals (e.g., signals 124) received from the transmitters. Such a transmitter typically transmits a signal marked with a repeating pseudo-random noise (PN) code of a set number of chips. While typically located in SVs 112, transmitters may sometimes be located on ground-based control stations, base stations 102, and/or other UEs 104. A UE 104 may include one or more dedicated receivers specifically designed to receive signals 124 for deriving geo location information from the SVs 112.

In a satellite positioning system, the use of signals 124 can be augmented by various satellite-based augmentation systems (SBAS) that may be associated with or otherwise enabled for use with one or more global and/or regional navigation satellite systems. For example an SBAS may include an augmentation system(s) that provides integrity information, differential corrections, etc., such as the Wide Area Augmentation System (WAAS), the European Geostationary Navigation Overlay Service (EGNOS), the Multi-functional Satellite Augmentation System (MSAS), the Global Positioning System (GPS) Aided Geo Augmented Navigation or GPS and Geo Augmented Navigation system (GAGAN), and/or the like. Thus, as used herein, a satellite positioning system may include any combination of one or more global and/or regional navigation satellites associated with such one or more satellite positioning systems.

In an aspect, SVs 112 may additionally or alternatively be part of one or more non-terrestrial networks (NTNs). In an NTN, an SV 112 is connected to an earth station (also referred to as a ground station, NTN gateway, or gateway), which in turn is connected to an element in a 5G network, such as a modified base station 102 (without a terrestrial antenna) or a network node in a 5GC. This element would in turn provide access to other elements in the 5G network and ultimately to entities external to the 5G network, such as Internet web servers and other user devices. In that way, a UE 104 may receive communication signals (e.g., signals 124) from an SV 112 instead of, or in addition to, communication signals from a terrestrial base station 102.

The wireless communications system 100 may further include one or more UEs, such as UE 190, that connects indirectly to one or more communication networks via one or more device-to-device (D2D) peer-to-peer (P2P) links (referred to as “sidelinks”). In the example of FIG. 1 , UE 190 has a D2D P2P link 192 with one of the UEs 104 connected to one of the base stations 102 (e.g., through which UE 190 may indirectly obtain cellular connectivity) and a D2D P2P link 194 with WLAN STA 152 connected to the WLAN AP 150 (through which UE 190 may indirectly obtain WLAN-based Internet connectivity). In an example, the D2D P2P links 192 and 194 may be supported with any well-known D2D RAT, such as LTE Direct (LTE-D), WiFi Direct (WiFi-D), Bluetooth®, and so on.

FIG. 2A illustrates an example wireless network structure 200. For example, a 5GC 210 (also referred to as a Next Generation Core (NGC)) can be viewed functionally as control plane (C-plane) functions 214 (e.g., UE registration, authentication, network access, gateway selection, etc.) and user plane (U-plane) functions 212, (e.g., UE gateway function, access to data networks, IP routing, etc.) which operate cooperatively to form the core network. User plane interface (NG-U) 213 and control plane interface (NG-C) 215 connect the gNB 222 to the 5GC 210 and specifically to the user plane functions 212 and control plane functions 214, respectively. In an additional configuration, an ng-eNB 224 may also be connected to the 5GC 210 via NG-C 215 to the control plane functions 214 and NG-U 213 to user plane functions 212. Further, ng-eNB 224 may directly communicate with gNB 222 via a backhaul connection 223. In some configurations, a Next Generation RAN (NG-RAN) 220 may have one or more gNBs 222, while other configurations include one or more of both ng-eNBs 224 and gNBs 222. Either (or both) gNB 222 or ng-eNB 224 may communicate with one or more UEs 204 (e.g., any of the UEs described herein).

Another optional aspect may include a location server 230, which may be in communication with the 5GC 210 to provide location assistance for UE(s) 204. The location server 230 can be implemented as a plurality of separate servers (e.g., physically separate servers, different software modules on a single server, different software modules spread across multiple physical servers, etc.), or alternately may each correspond to a single server. The location server 230 can be configured to support one or more location services for UEs 204 that can connect to the location server 230 via the core network, 5GC 210, and/or via the Internet (not illustrated). Further, the location server 230 may be integrated into a component of the core network, or alternatively may be external to the core network (e.g., a third party server, such as an original equipment manufacturer (OEM) server or service server).

FIG. 2B illustrates another example wireless network structure 250. A 5GC 260 (which may correspond to 5GC 210 in FIG. 2A) can be viewed functionally as control plane functions, provided by an access and mobility management function (AMF) 264, and user plane functions, provided by a user plane function (UPF) 262, which operate cooperatively to form the core network (i.e., 5GC 260). The functions of the AMF 264 include registration management, connection management, reachability management, mobility management, lawful interception, transport for session management (SM) messages between one or more UEs 204 (e.g., any of the UEs described herein) and a session management function (SMF) 266, transparent proxy services for routing SM messages, access authentication and access authorization, transport for short message service (SMS) messages between the UE 204 and the short message service function (SMSF) (not shown), and security anchor functionality (SEAF). The AMF 264 also interacts with an authentication server function (AUSF) (not shown) and the UE 204, and receives the intermediate key that was established as a result of the UE 204 authentication process. In the case of authentication based on a UMTS (universal mobile telecommunications system) subscriber identity module (USIM), the AMF 264 retrieves the security material from the AUSF. The functions of the AMF 264 also include security context management (SCM). The SCM receives a key from the SEAF that it uses to derive access-network specific keys. The functionality of the AMF 264 also includes location services management for regulatory services, transport for location services messages between the UE 204 and a location management function (LMF) 270 (which acts as a location server 230), transport for location services messages between the NG-RAN 220 and the LMF 270, evolved packet system (EPS) bearer identifier allocation for interworking with the EPS, and UE 204 mobility event notification. In addition, the AMF 264 also supports functionalities for non-3GPP (Third Generation Partnership Project) access networks.

Functions of the UPF 262 include acting as an anchor point for intra-/inter-RAT mobility (when applicable), acting as an external protocol data unit (PDU) session point of interconnect to a data network (not shown), providing packet routing and forwarding, packet inspection, user plane policy rule enforcement (e.g., gating, redirection, traffic steering), lawful interception (user plane collection), traffic usage reporting, quality of service (QoS) handling for the user plane (e.g., uplink/downlink rate enforcement, reflective QoS marking in the downlink), uplink traffic verification (service data flow (SDF) to QoS flow mapping), transport level packet marking in the uplink and downlink, downlink packet buffering and downlink data notification triggering, and sending and forwarding of one or more “end markers” to the source RAN node. The UPF 262 may also support transfer of location services messages over a user plane between the UE 204 and a location server, such as an SLP 272.

The functions of the SMF 266 include session management, UE Internet protocol (IP) address allocation and management, selection and control of user plane functions, configuration of traffic steering at the UPF 262 to route traffic to the proper destination, control of part of policy enforcement and QoS, and downlink data notification. The interface over which the SMF 266 communicates with the AMF 264 is referred to as the N11 interface.

Another optional aspect may include an LMF 270, which may be in communication with the 5GC 260 to provide location assistance for UEs 204. The LMF 270 can be implemented as a plurality of separate servers (e.g., physically separate servers, different software modules on a single server, different software modules spread across multiple physical servers, etc.), or alternately may each correspond to a single server. The LMF 270 can be configured to support one or more location services for UEs 204 that can connect to the LMF 270 via the core network, 5GC 260, and/or via the Internet (not illustrated). The SLP 272 may support similar functions to the LMF 270, but whereas the LMF 270 may communicate with the AMF 264, NG-RAN 220, and UEs 204 over a control plane (e.g., using interfaces and protocols intended to convey signaling messages and not voice or data), the SLP 272 may communicate with UEs 204 and external clients (e.g., third-party server 274) over a user plane (e.g., using protocols intended to carry voice and/or data like the transmission control protocol (TCP) and/or IP).

Yet another optional aspect may include a third-party server 274, which may be in communication with the LMF 270, the SLP 272, the 5GC 260 (e.g., via the AMF 264 and/or the UPF 262), the NG-RAN 220, and/or the UE 204 to obtain location information (e.g., a location estimate) for the UE 204. As such, in some cases, the third-party server 274 may be referred to as a location services (LCS) client or an external client. The third-party server 274 can be implemented as a plurality of separate servers (e.g., physically separate servers, different software modules on a single server, different software modules spread across multiple physical servers, etc.), or alternately may each correspond to a single server.

User plane interface 263 and control plane interface 265 connect the 5GC 260, and specifically the UPF 262 and AMF 264, respectively, to one or more gNBs 222 and/or ng-eNBs 224 in the NG-RAN 220. The interface between gNB(s) 222 and/or ng-eNB(s) 224 and the AMF 264 is referred to as the “N2” interface, and the interface between gNB(s) 222 and/or ng-eNB(s) 224 and the UPF 262 is referred to as the “N3” interface. The gNB(s) 222 and/or ng-eNB(s) 224 of the NG-RAN 220 may communicate directly with each other via backhaul connections 223, referred to as the “Xn-C” interface. One or more of gNBs 222 and/or ng-eNBs 224 may communicate with one or more UEs 204 over a wireless interface, referred to as the “Uu” interface.

The functionality of a gNB 222 may be divided between a gNB central unit (gNB-CU) 226, one or more gNB distributed units (gNB-DUs) 228, and one or more gNB radio units (gNB-RUs) 229. A gNB-CU 226 is a logical node that includes the base station functions of transferring user data, mobility control, radio access network sharing, positioning, session management, and the like, except for those functions allocated exclusively to the gNB-DU(s) 228. More specifically, the gNB-CU 226 generally host the radio resource control (RRC), service data adaptation protocol (SDAP), and packet data convergence protocol (PDCP) protocols of the gNB 222. A gNB-DU 228 is a logical node that generally hosts the radio link control (RLC) and medium access control (MAC) layer of the gNB 222. Its operation is controlled by the gNB-CU 226. One gNB-DU 228 can support one or more cells, and one cell is supported by only one gNB-DU 228. The interface 232 between the gNB-CU 226 and the one or more gNB-DUs 228 is referred to as the “F 1” interface. The physical (PHY) layer functionality of a gNB 222 is generally hosted by one or more standalone gNB-RUs 229 that perform functions such as power amplification and signal transmission/reception. The interface between a gNB-DU 228 and a gNB-RU 229 is referred to as the “Fx” interface. Thus, a UE 204 communicates with the gNB-CU 226 via the RRC, SDAP, and PDCP layers, with a gNB-DU 228 via the RLC and MAC layers, and with a gNB-RU 229 via the PHY layer.

FIGS. 3A, 3B, and 3C illustrate several example components (represented by corresponding blocks) that may be incorporated into a UE 302 (which may correspond to any of the UEs described herein), a base station 304 (which may correspond to any of the base stations described herein), and a network entity 306 (which may correspond to or embody any of the network functions described herein, including the location server 230 and the LMF 270, or alternatively may be independent from the NG-RAN 220 and/or 5GC 210/260 infrastructure depicted in FIGS. 2A and 2B, such as a private network) to support the file transmission operations as taught herein. It will be appreciated that these components may be implemented in different types of apparatuses in different implementations (e.g., in an ASIC, in a system-on-chip (SoC), etc.). The illustrated components may also be incorporated into other apparatuses in a communication system. For example, other apparatuses in a system may include components similar to those described to provide similar functionality. Also, a given apparatus may contain one or more of the components. For example, an apparatus may include multiple transceiver components that enable the apparatus to operate on multiple carriers and/or communicate via different technologies.

The UE 302 and the base station 304 each include one or more wireless wide area network (WWAN) transceivers 310 and 350, respectively, providing means for communicating (e.g., means for transmitting, means for receiving, means for measuring, means for tuning, means for refraining from transmitting, etc.) via one or more wireless communication networks (not shown), such as an NR network, an LTE network, a GSM network, and/or the like. The WWAN transceivers 310 and 350 may each be connected to one or more antennas 316 and 356, respectively, for communicating with other network nodes, such as other UEs, access points, base stations (e.g., eNBs, gNBs), etc., via at least one designated RAT (e.g., NR, LTE, GSM, etc.) over a wireless communication medium of interest (e.g., some set of time/frequency resources in a particular frequency spectrum). The WWAN transceivers 310 and 350 may be variously configured for transmitting and encoding signals 318 and 358 (e.g., messages, indications, information, and so on), respectively, and, conversely, for receiving and decoding signals 318 and 358 (e.g., messages, indications, information, pilots, and so on), respectively, in accordance with the designated RAT. Specifically, the WWAN transceivers 310 and 350 include one or more transmitters 314 and 354, respectively, for transmitting and encoding signals 318 and 358, respectively, and one or more receivers 312 and 352, respectively, for receiving and decoding signals 318 and 358, respectively.

The UE 302 and the base station 304 each also include, at least in some cases, one or more short-range wireless transceivers 320 and 360, respectively. The short-range wireless transceivers 320 and 360 may be connected to one or more antennas 326 and 366, respectively, and provide means for communicating (e.g., means for transmitting, means for receiving, means for measuring, means for tuning, means for refraining from transmitting, etc.) with other network nodes, such as other UEs, access points, base stations, etc., via at least one designated RAT (e.g., WiFi, LTE-D, Bluetooth®, Zigbee®, Z-Wave®, PCS, dedicated short-range communications (DSRC), wireless access for vehicular environments (WAVE), near-field communication (NFC), etc.) over a wireless communication medium of interest. The short-range wireless transceivers 320 and 360 may be variously configured for transmitting and encoding signals 328 and 368 (e.g., messages, indications, information, and so on), respectively, and, conversely, for receiving and decoding signals 328 and 368 (e.g., messages, indications, information, pilots, and so on), respectively, in accordance with the designated RAT. Specifically, the short-range wireless transceivers 320 and 360 include one or more transmitters 324 and 364, respectively, for transmitting and encoding signals 328 and 368, respectively, and one or more receivers 322 and 362, respectively, for receiving and decoding signals 328 and 368, respectively. As specific examples, the short-range wireless transceivers 320 and 360 may be WiFi transceivers, Bluetooth® transceivers, Zigbee® and/or Z-Wave® transceivers, NFC transceivers, or vehicle-to-vehicle (V2V) and/or vehicle-to-everything (V2X) transceivers.

The UE 302 and the base station 304 also include, at least in some cases, satellite signal receivers 330 and 370. The satellite signal receivers 330 and 370 may be connected to one or more antennas 336 and 376, respectively, and may provide means for receiving and/or measuring satellite positioning/communication signals 338 and 378, respectively. Where the satellite signal receivers 330 and 370 are satellite positioning system receivers, the satellite positioning/communication signals 338 and 378 may be global positioning system (GPS) signals, global navigation satellite system (GLONASS) signals, Galileo signals, Beidou signals, Indian Regional Navigation Satellite System (NAVIC), Quasi-Zenith Satellite System (QZSS), etc. Where the satellite signal receivers 330 and 370 are non-terrestrial network (NTN) receivers, the satellite positioning/communication signals 338 and 378 may be communication signals (e.g., carrying control and/or user data) originating from a 5G network. The satellite signal receivers 330 and 370 may comprise any suitable hardware and/or software for receiving and processing satellite positioning/communication signals 338 and 378, respectively. The satellite signal receivers 330 and 370 may request information and operations as appropriate from the other systems, and, at least in some cases, perform calculations to determine locations of the UE 302 and the base station 304, respectively, using measurements obtained by any suitable satellite positioning system algorithm.

The base station 304 and the network entity 306 each include one or more network transceivers 380 and 390, respectively, providing means for communicating (e.g., means for transmitting, means for receiving, etc.) with other network entities (e.g., other base stations 304, other network entities 306). For example, the base station 304 may employ the one or more network transceivers 380 to communicate with other base stations 304 or network entities 306 over one or more wired or wireless backhaul links. As another example, the network entity 306 may employ the one or more network transceivers 390 to communicate with one or more base station 304 over one or more wired or wireless backhaul links, or with other network entities 306 over one or more wired or wireless core network interfaces.

A transceiver may be configured to communicate over a wired or wireless link. A transceiver (whether a wired transceiver or a wireless transceiver) includes transmitter circuitry (e.g., transmitters 314, 324, 354, 364) and receiver circuitry (e.g., receivers 312, 322, 352, 362). A transceiver may be an integrated device (e.g., embodying transmitter circuitry and receiver circuitry in a single device) in some implementations, may comprise separate transmitter circuitry and separate receiver circuitry in some implementations, or may be embodied in other ways in other implementations. The transmitter circuitry and receiver circuitry of a wired transceiver (e.g., network transceivers 380 and 390 in some implementations) may be coupled to one or more wired network interface ports. Wireless transmitter circuitry (e.g., transmitters 314, 324, 354, 364) may include or be coupled to a plurality of antennas (e.g., antennas 316, 326, 356, 366), such as an antenna array, that permits the respective apparatus (e.g., UE 302, base station 304) to perform transmit “beamforming,” as described herein. Similarly, wireless receiver circuitry (e.g., receivers 312, 322, 352, 362) may include or be coupled to a plurality of antennas (e.g., antennas 316, 326, 356, 366), such as an antenna array, that permits the respective apparatus (e.g., UE 302, base station 304) to perform receive beamforming, as described herein. In an aspect, the transmitter circuitry and receiver circuitry may share the same plurality of antennas (e.g., antennas 316, 326, 356, 366), such that the respective apparatus can only receive or transmit at a given time, not both at the same time. A wireless transceiver (e.g., WWAN transceivers 310 and 350, short-range wireless transceivers 320 and 360) may also include a network listen module (NLM) or the like for performing various measurements.

As used herein, the various wireless transceivers (e.g., transceivers 310, 320, 350, and 360, and network transceivers 380 and 390 in some implementations) and wired transceivers (e.g., network transceivers 380 and 390 in some implementations) may generally be characterized as “a transceiver,” “at least one transceiver,” or “one or more transceivers.” As such, whether a particular transceiver is a wired or wireless transceiver may be inferred from the type of communication performed. For example, backhaul communication between network devices or servers will generally relate to signaling via a wired transceiver, whereas wireless communication between a UE (e.g., UE 302) and a base station (e.g., base station 304) will generally relate to signaling via a wireless transceiver.

The UE 302, the base station 304, and the network entity 306 also include other components that may be used in conjunction with the operations as disclosed herein. The UE 302, the base station 304, and the network entity 306 include one or more processors 332, 384, and 394, respectively, for providing functionality relating to, for example, wireless communication, and for providing other processing functionality. The processors 332, 384, and 394 may therefore provide means for processing, such as means for determining, means for calculating, means for receiving, means for transmitting, means for indicating, etc. In an aspect, the processors 332, 384, and 394 may include, for example, one or more general purpose processors, multi-core processors, central processing units (CPUs), ASICs, digital signal processors (DSPs), field programmable gate arrays (FPGAs), other programmable logic devices or processing circuitry, or various combinations thereof.

The UE 302, the base station 304, and the network entity 306 include memory circuitry implementing memories 340, 386, and 396 (e.g., each including a memory device), respectively, for maintaining information (e.g., information indicative of reserved resources, thresholds, parameters, and so on). The memories 340, 386, and 396 may therefore provide means for storing, means for retrieving, means for maintaining, etc. In some cases, the UE 302, the base station 304, and the network entity 306 may include waveform component 342, 388, and 398, respectively. The waveform component 342, 388, and 398 may be hardware circuits that are part of or coupled to the processors 332, 384, and 394, respectively, that, when executed, cause the UE 302, the base station 304, and the network entity 306 to perform the functionality described herein. In other aspects, the waveform component 342, 388, and 398 may be external to the processors 332, 384, and 394 (e.g., part of a modem processing system, integrated with another processing system, etc.). Alternatively, the waveform component 342, 388, and 398 may be memory modules stored in the memories 340, 386, and 396, respectively, that, when executed by the processors 332, 384, and 394 (or a modem processing system, another processing system, etc.), cause the UE 302, the base station 304, and the network entity 306 to perform the functionality described herein. FIG. 3A illustrates possible locations of the waveform component 342, which may be, for example, part of the one or more WWAN transceivers 310, the memory 340, the one or more processors 332, or any combination thereof, or may be a standalone component. FIG. 3B illustrates possible locations of the waveform component 388, which may be, for example, part of the one or more WWAN transceivers 350, the memory 386, the one or more processors 384, or any combination thereof, or may be a standalone component. FIG. 3C illustrates possible locations of the waveform component 398, which may be, for example, part of the one or more network transceivers 390, the memory 396, the one or more processors 394, or any combination thereof, or may be a standalone component.

The UE 302 may include one or more sensors 344 coupled to the one or more processors 332 to provide means for sensing or detecting movement and/or orientation information that is independent of motion data derived from signals received by the one or more WWAN transceivers 310, the one or more short-range wireless transceivers 320, and/or the satellite signal receiver 330. By way of example, the sensor(s) 344 may include an accelerometer (e.g., a micro-electrical mechanical systems (MEMS) device), a gyroscope, a geomagnetic sensor (e.g., a compass), an altimeter (e.g., a barometric pressure altimeter), and/or any other type of movement detection sensor. Moreover, the sensor(s) 344 may include a plurality of different types of devices and combine their outputs in order to provide motion information. For example, the sensor(s) 344 may use a combination of a multi-axis accelerometer and orientation sensors to provide the ability to compute positions in two-dimensional (2D) and/or three-dimensional (3D) coordinate systems.

In addition, the UE 302 includes a user interface 346 providing means for providing indications (e.g., audible and/or visual indications) to a user and/or for receiving user input (e.g., upon user actuation of a sensing device such a keypad, a touch screen, a microphone, and so on). Although not shown, the base station 304 and the network entity 306 may also include user interfaces.

Referring to the one or more processors 384 in more detail, in the downlink, IP packets from the network entity 306 may be provided to the processor 384. The one or more processors 384 may implement functionality for an RRC layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. The one or more processors 384 may provide RRC layer functionality associated with broadcasting of system information (e.g., master information block (MIB), system information blocks (SIBs)), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter-RAT mobility, and measurement configuration for UE measurement reporting; PDCP layer functionality associated with header compression/decompression, security (ciphering, deciphering, integrity protection, integrity verification), and handover support functions; RLC layer functionality associated with the transfer of upper layer PDUs, error correction through automatic repeat request (ARQ), concatenation, segmentation, and reassembly of RLC service data units (SDUs), re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, scheduling information reporting, error correction, priority handling, and logical channel prioritization.

The transmitter 354 and the receiver 352 may implement Layer-1 (L1) functionality associated with various signal processing functions. Layer-1, which includes a physical (PHY) layer, may include error detection on the transport channels, forward error correction (FEC) coding/decoding of the transport channels, interleaving, rate matching, mapping onto physical channels, modulation/demodulation of physical channels, and MIMO antenna processing. The transmitter 354 handles mapping to signal constellations based on various modulation schemes (e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), M-phase-shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM)). The coded and modulated symbols may then be split into parallel streams. Each stream may then be mapped to an orthogonal frequency division multiplexing (OFDM) subcarrier, multiplexed with a reference signal (e.g., pilot) in the time and/or frequency domain, and then combined together using an inverse fast Fourier transform (IFFT) to produce a physical channel carrying a time domain OFDM symbol stream. The OFDM symbol stream is spatially precoded to produce multiple spatial streams. Channel estimates from a channel estimator may be used to determine the coding and modulation scheme, as well as for spatial processing. The channel estimate may be derived from a reference signal and/or channel condition feedback transmitted by the UE 302. Each spatial stream may then be provided to one or more different antennas 356. The transmitter 354 may modulate an RF carrier with a respective spatial stream for transmission.

At the UE 302, the receiver 312 receives a signal through its respective antenna(s) 316. The receiver 312 recovers information modulated onto an RF carrier and provides the information to the one or more processors 332. The transmitter 314 and the receiver 312 implement Layer-1 functionality associated with various signal processing functions. The receiver 312 may perform spatial processing on the information to recover any spatial streams destined for the UE 302. If multiple spatial streams are destined for the UE 302, they may be combined by the receiver 312 into a single OFDM symbol stream. The receiver 312 then converts the OFDM symbol stream from the time-domain to the frequency domain using a fast Fourier transform (FFT). The frequency domain signal comprises a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, and the reference signal, are recovered and demodulated by determining the most likely signal constellation points transmitted by the base station 304. These soft decisions may be based on channel estimates computed by a channel estimator. The soft decisions are then decoded and de-interleaved to recover the data and control signals that were originally transmitted by the base station 304 on the physical channel. The data and control signals are then provided to the one or more processors 332, which implements Layer-3 (L3) and Layer-2 (L2) functionality.

In the uplink, the one or more processors 332 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, and control signal processing to recover IP packets from the core network. The one or more processors 332 are also responsible for error detection.

Similar to the functionality described in connection with the downlink transmission by the base station 304, the one or more processors 332 provides RRC layer functionality associated with system information (e.g., MIB, SIBs) acquisition, RRC connections, and measurement reporting; PDCP layer functionality associated with header compression/decompression, and security (ciphering, deciphering, integrity protection, integrity verification); RLC layer functionality associated with the transfer of upper layer PDUs, error correction through ARQ, concatenation, segmentation, and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs), demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through hybrid automatic repeat request (HARD), priority handling, and logical channel prioritization.

Channel estimates derived by the channel estimator from a reference signal or feedback transmitted by the base station 304 may be used by the transmitter 314 to select the appropriate coding and modulation schemes, and to facilitate spatial processing. The spatial streams generated by the transmitter 314 may be provided to different antenna(s) 316. The transmitter 314 may modulate an RF carrier with a respective spatial stream for transmission.

The uplink transmission is processed at the base station 304 in a manner similar to that described in connection with the receiver function at the UE 302. The receiver 352 receives a signal through its respective antenna(s) 356. The receiver 352 recovers information modulated onto an RF carrier and provides the information to the one or more processors 384.

In the uplink, the one or more processors 384 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover IP packets from the UE 302. IP packets from the one or more processors 384 may be provided to the core network. The one or more processors 384 are also responsible for error detection.

For convenience, the UE 302, the base station 304, and/or the network entity 306 are shown in FIGS. 3A, 3B, and 3C as including various components that may be configured according to the various examples described herein. It will be appreciated, however, that the illustrated components may have different functionality in different designs. In particular, various components in FIGS. 3A to 3C are optional in alternative configurations and the various aspects include configurations that may vary due to design choice, costs, use of the device, or other considerations. For example, in case of FIG. 3A, a particular implementation of UE 302 may omit the WWAN transceiver(s) 310 (e.g., a wearable device or tablet computer or PC or laptop may have Wi-Fi and/or Bluetooth capability without cellular capability), or may omit the short-range wireless transceiver(s) 320 (e.g., cellular-only, etc.), or may omit the satellite signal receiver 330, or may omit the sensor(s) 344, and so on. In another example, in case of FIG. 3B, a particular implementation of the base station 304 may omit the WWAN transceiver(s) 350 (e.g., a Wi-Fi “hotspot” access point without cellular capability), or may omit the short-range wireless transceiver(s) 360 (e.g., cellular-only, etc.), or may omit the satellite receiver 370, and so on. For brevity, illustration of the various alternative configurations is not provided herein, but would be readily understandable to one skilled in the art.

The various components of the UE 302, the base station 304, and the network entity 306 may be communicatively coupled to each other over data buses 334, 382, and 392, respectively. In an aspect, the data buses 334, 382, and 392 may form, or be part of, a communication interface of the UE 302, the base station 304, and the network entity 306, respectively. For example, where different logical entities are embodied in the same device (e.g., gNB and location server functionality incorporated into the same base station 304), the data buses 334, 382, and 392 may provide communication between them.

The components of FIGS. 3A, 3B, and 3C may be implemented in various ways. In some implementations, the components of FIGS. 3A, 3B, and 3C may be implemented in one or more circuits such as, for example, one or more processors and/or one or more ASICs (which may include one or more processors). Here, each circuit may use and/or incorporate at least one memory component for storing information or executable code used by the circuit to provide this functionality. For example, some or all of the functionality represented by blocks 310 to 346 may be implemented by processor and memory component(s) of the UE 302 (e.g., by execution of appropriate code and/or by appropriate configuration of processor components). Similarly, some or all of the functionality represented by blocks 350 to 388 may be implemented by processor and memory component(s) of the base station 304 (e.g., by execution of appropriate code and/or by appropriate configuration of processor components). Also, some or all of the functionality represented by blocks 390 to 398 may be implemented by processor and memory component(s) of the network entity 306 (e.g., by execution of appropriate code and/or by appropriate configuration of processor components). For simplicity, various operations, acts, and/or functions are described herein as being performed “by a UE,” “by a base station,” “by a network entity,” etc. However, as will be appreciated, such operations, acts, and/or functions may actually be performed by specific components or combinations of components of the UE 302, base station 304, network entity 306, etc., such as the processors 332, 384, 394, the transceivers 310, 320, 350, and 360, the memories 340, 386, and 396, the waveform component 342, 388, and 398, etc.

In some designs, the network entity 306 may be implemented as a core network component. In other designs, the network entity 306 may be distinct from a network operator or operation of the cellular network infrastructure (e.g., NG RAN 220 and/or 5GC 210/260). For example, the network entity 306 may be a component of a private network that may be configured to communicate with the UE 302 via the base station 304 or independently from the base station 304 (e.g., over a non-cellular communication link, such as WiFi).

In wireless communication, waveforms may be transmitted with a guard interval (GI) or a cyclic prefix (CP) or some combination. For both GI-based waveforms and CP-based waveforms, linear convolution on transmission (Tx) symbols of a channel are converted to a circle convolution (e.g., simple one-tap frequency domain equalization at the receiver). The general objective of the CP or GI is to reduce or avoid inter-symbol interference, maintain symbol/slot alignment. CP is used frequency in protocols such as LTE, NR, and Wi-Fi OFDM, while Gi is used in protocols such as 802.11 ad/ay for Single-Carrier Frequency Domain Equalization (SC-FDE).

FIG. 4 depicts waveform configurations 400 in accordance with aspects of the disclosure. At 410, a CP-based waveform is depicted, which includes a CP 420 (e.g., which copies or mirrors the last few bits of the waveform at 430), whereby the CP falls outside of a Differential Fourier Transform (DFT) window. At 440, a GI-based waveform is depicted, which includes a GI 450 inside of the DFT window.

FIG. 5 depicts slot configurations 500 in accordance with aspects of the disclosure. At 510, a slot configuration is shown with a number of CP-based waveforms (e.g., such as CP-based waveform 410 of FIG. 4 ). The various CPs may be of different lengths and/or types (e.g., normal CP (NCP) may include 14 OFDM symbols per slot, Enhanced CP (ECP) may include 12 OFDM symbols per slot, etc.). At 520, a slot configuration is shown with a number of GI-based waveforms (e.g., such as GI-based waveform 440 of FIG. 4 ), with the GI of the initial GI-based waveform being outside of the slot. In some designs, 15 symbols per slot with same GI length as NCP (unform GI length across symbols) may be used.

Referring to FIG. 5 , CP-based slot configurations are self-contained and may include random data, and as such may not be readily adaptable to delay spreads. GI-based slot configurations are associated with a known sequence (e.g., beneficial to synchronization and phase tracking) and are more efficient in terms of resource consumption compared to CP-based slot configurations. GI-based slot configurations are also more readily adaptable to delay spread without changing symbol durations.

Since GI-based waveform can adapt to different delay spread without changing symbol duration, the known GI waveform can be used to achieve better resource utilization. In some designs, GI-based waveforms may be implemented with DFT. For example, a GI-based waveform may be implemented as a zero-tail DFT-spread-OFDM signal, whereby zeros are added to the end or ‘tail’ of the GI-based waveform prior to DFT input. The goal of adding the zero tail is to achieve flexible adaptation to delay spread. However, a zero-sample GI-based waveform may not be useable for features such as tracking, channel estimation, and so on. Also, due to oversampling (different DFT and Inverse Fast Fourier Transform (IFFT) size), the GI in IFFT output are not zero samples anymore, which introduces an imperfection on the circular property for FFT operation.

In some designs, non-zero redundant symbols (a function of the data symbols) may be added prior to DFT to suppress the tail energy due to leakage from oversampling. The GI sequences (w) are added prior to DFT so no need for GI cancellation in an attempt to achieve a perfect circular property. However, GI sequences prior to DFT is superposed with data input (e.g., need to perform FFT, tone extraction, equalization and IFFT, etc.).

FIG. 6 illustrates a GI-based waveform generation procedure 600 in accordance with an aspect of the disclosure. In FIG. 6 , data (d), a leakage suppression signal (s) and a GI sequence or unique word (w) are input to a DFT component 610. The output of the DFT component 610 is then input to an IFFT component 620, along with 0s to form the zero-tail. The IFFT component 620 outputs a GI-based waveform (x), which includes both a zero tail part and a non-zero part, which may then be transmitted.

Referring to FIG. 6 , assume A as IFFT (F^(H)), subcarrier mapping (B) and DFT matrix (D): A=F^(H) B D. The IFFT output becomes:

$\begin{matrix} {x = {{A\begin{bmatrix} d \\ s \\ w \end{bmatrix}} = {{\begin{bmatrix} M_{11} & M_{12} & M_{13} \\ M_{21} & M_{22} & M_{23} \end{bmatrix}\begin{bmatrix} d \\ s \\ w \end{bmatrix}} = \begin{bmatrix} x_{{non} - {tail}} \\ x_{tail} \end{bmatrix}}}} & {{Equation}1} \end{matrix}$

To suppress the data leakage to the GI sequences, the following relationship may be used:

M ₂₂ s+M ₂₁ d=0   Equation 2

As can be observed from Equation 2, the suppression signal (s) is a function of RB allocation as well as the oversampling ratio.

Aspects of the disclosure are directed to GI-based waveforms that are generated based on pre-processing (i.e., before DFT) of the data (d), a leakage suppression signal (s) and a GI sequence or unique word (w). In particular, the data (d), a leakage suppression signal (s) and a GI sequence or unique word (w) can be mapped to a set of reserved time-domain resources based on a time-domain resource mapping and reservation rule to produce DFT input data, which may be used to further mitigate inter-symbol interference.

FIG. 7 illustrates an exemplary process 700 of wireless communication, according to aspects of the disclosure. In an aspect, the process 1400 may be performed by a wireless device, such as a UE (e.g., UE 302), a base station (e.g., BS 304), and so on.

At 710, the wireless device (e.g., waveform component 342 or 388, processor(s) 332 or 384, etc.) obtains data for transmission in a guard interval (GI)-based waveform with a data part (e.g., non-zero part) and a tail part (e.g., a zero tail part). For example, the data may correspond to data (d) as described above with respect to FIG. 6 .

At 720, the wireless device (e.g., waveform component 342 or 388, processor(s) 332 or 384, etc.) obtains a unique word (UW) sequence for the tail part (e.g., zero tail part). For example, the UW may correspond to GI sequence (w) as described above with respect to FIG. 6 . In some designs, the UW sequence may be a pre-defined sequence (e.g., a Zadoff-Chu sequence, a pseudo-noise (PN) sequence, etc.).

At 730, the wireless device (e.g., waveform component 342 or 388, processor(s) 332 or 384, etc.) obtains a suppression signal with filter coefficients configured to suppress leakage from the data part (e.g., non-zero part) to the tail part (e.g., zero tail part). For example, the UW sequence may correspond to suppression signal (s) as described above with respect to FIG. 6 . In some designs, the filter coefficients are defined before the mapping (e.g., the filter coefficients are generated before the time domain resource mapping/reservation based on the oversampling ratio).

At 740, the wireless device (e.g., waveform component 342 or 388, processor(s) 332 or 384, etc.) maps the data, the UW sequence, and the suppression signal to a set of reserved time-domain resources based on a time-domain resource mapping and reservation rule to produce Discrete Fourier Transform (DFT) input data. In some designs, the filter coefficients may be implemented so as to limit transmission power near the tail part (e.g., the zero tail part). Various examples of the mapping at 740 are described below in more detail. In some designs, some or all of the filter coefficients are defined as a function of the mapping (e.g., the initial filter coefficients may be modified, etc.).

At 750, the wireless device (e.g., waveform component 342 or 388, processor(s) 332 or 384, etc.) performs DFT processing on the DFT input data to produce Inverse Fast Fourier Transform (IFFT) input data.

At 760, the wireless device (e.g., waveform component 342 or 388, processor(s) 332 or 384, etc.) performs IFFT processing on the IFFT input data to produce the GI-based waveform with the data part (e.g., non-zero part) and the tail part (e.g., zero tail part).

At 770, the wireless device (e.g., transmitter 314 or 324 or 354 or 364, etc.) transmits the GI-based waveform.

FIG. 8 illustrates an example implementation 800 of the process 700 of FIG. 7 in accordance with aspects of the disclosure. As shown in FIG. 8 , data (d), a leakage suppression signal (s) and a GI sequence or unique word (w) are input to a pre-DFT processing component 810. The pre-processing component 810 maps the data, the UW sequence, and the suppression signal to a set of reserved time-domain resources based on a time-domain resource mapping and reservation rule to produce DFT input data, as in 740 of FIG. 7 . The output of the pre-processing component 810 is then provided as DFT input data to the DFT component 820. The output of the DFT component 820 is then input to an IFFT component 830, along with 0s to form the zero-tail. The IFFT component 830 outputs a GI-based waveform (x), which includes both a tail part (e.g., zero tail part) and a data part (e.g., non-zero part), which may then be transmitted.

Referring to FIG. 7 , in some designs, with the time domain resource mapping and reservation, the IFFT output becomes:

$\begin{matrix} {x = {{A\begin{bmatrix} d_{p} \\ s_{p} \\ w \end{bmatrix}} = {\begin{bmatrix} M_{11} & M_{12} & M_{13} \\ M_{21} & M_{22} & M_{23} \end{bmatrix}{{\begin{bmatrix} d_{p} \\ s_{p} \\ w \end{bmatrix} = {{\begin{bmatrix} M_{11,P} & M_{12,p} & M_{13} \\ M_{21,P} & M_{22,p} & M_{23} \end{bmatrix}\begin{bmatrix} d \\ s \\ w \end{bmatrix}} = \begin{bmatrix} x_{{non} - {tail}} \\ x_{tail} \end{bmatrix}}}}}}} & {{Equation}3} \end{matrix}$

whereby d_(p) and s_(p) are the data and suppression signal after time domain resource mapping and reservation, and M_(21,P) and M_(22,P) are the oversampling matrix after time domain resource mapping and reservation.

In some designs, to suppress the data leakage to the GI sequences, the following relationship may be obtained:

M _(22,P) s+M _(21,P) d=0   Equation 4

In some designs, the time domain resource mapping and reservation can be designed to allow efficient implementation of suppression signal. In some designs, the relationship of M_(22,P)s+M_(21,P)d=0 need not be used. For example, M_(22,P)s+M_(21,P)d may alternatively be kept below some threshold (e.g., M_(22,P)s+M_(21,P)d may be kept reasonably small compared to the signal energy). In some designs, gNB can configure the exact time domain resources to map the suppression signal (i.e., which and how many time domain resources to send the suppression signal on the DFT input).

Referring to FIG. 7 , in some designs, the filter coefficients are predetermined based on the time-domain resource mapping and reservation rule, an oversampling ratio and a starting time-domain resource among the set of time-domain resources (e.g., and then stored). Then, when a transmission is performed, the predetermined filter coefficients can be retrieved from storage and used for the mapping at 740 of FIG. 7 . In some designs, the number of predetermined filter coefficients may be kept below some threshold (e.g., equal to a number of different RB configurations, with each RB configuration associated with a particular predetermined filter coefficient).

Referring to FIG. 7 , in some designs, an initial set of filter coefficients is predetermined based on the time-domain resource mapping and reservation rule and an oversampling ratio. Then, the filter coefficients are dynamically derived at 740 of FIG. 7 (e.g., in real-time or on-the-fly) based on the initial set of filter coefficients and a starting time-domain resource among the set of time-domain resources.

Referring to FIG. 7 , in some designs, the wireless device may obtain a set of candidate filter coefficients, and may set any candidate filter coefficient in the set of candidate filter coefficients that is below a threshold to zero to produce the filter coefficients for the suppression signal. For example, this may help to reduce complexity. In some designs, due to the pattern of A matrix, only the filter coefficients that affect the first and last few samples of d may be selected.

Referring to FIG. 7 , in some designs, each filter coefficient of the filter coefficients of the suppression signal may be defined based on a set of values associated with a set of adjacent neighbors. In some designs, each filter coefficient of the filter coefficients of the suppression signal is defined based on an average of the set of values associated with the set of adjacent neighbors. A more detailed example of this aspect is provided below.

In general, computation of M_(22,P)s+M_(21,P)d involves matrix inversion and matrix multiplication. In some designs, a degree of leakage suppression may be implemented as a tradeoff with respect to implementation complexity. Assume that all the samples more than N modulation symbol(s) away from the start of the tail have negligible impact (e.g., due to the synchronization oversampling with DFT and IFFT operation, there may still be leakage for the modulation symbols N samples away from the start of the tail; however, such residual leakage may be tolerated to reduce the complexity). The suppression signal may then be determined based on linear combination of its non-zero N neighbors. In some designs, to further reduce the complexity, the linear coefficients can be chosen such that it is a binary operation (i.e., ½, ¼, etc.).

For example, assume the original signal before DFT and including the zero tail is d₀ d₁ d₂d₃d₄d₅d₆00000. Now, assume the actual signal with time domain resource reservation for suppression signal as d₀ d₁ d₂d₃s₀d₅s₁ 00000. Instead of deriving the suppression signal s₀, s₁ based on minimum mean-square error (MMSE), the simple approximation can be as s₀=−(d₃+d₅)/2, s₁=−(d₅)/2. In this case, the suppression signal can be derived up to the two adjacent neighbors (N=2). However, in other designs, N=1 or N>2.

In the detailed description above it can be seen that different features are grouped together in examples. This manner of disclosure should not be understood as an intention that the example clauses have more features than are explicitly mentioned in each clause. Rather, the various aspects of the disclosure may include fewer than all features of an individual example clause disclosed. Therefore, the following clauses should hereby be deemed to be incorporated in the description, wherein each clause by itself can stand as a separate example. Although each dependent clause can refer in the clauses to a specific combination with one of the other clauses, the aspect(s) of that dependent clause are not limited to the specific combination. It will be appreciated that other example clauses can also include a combination of the dependent clause aspect(s) with the subject matter of any other dependent clause or independent clause or a combination of any feature with other dependent and independent clauses. The various aspects disclosed herein expressly include these combinations, unless it is explicitly expressed or can be readily inferred that a specific combination is not intended (e.g., contradictory aspects, such as defining an element as both an insulator and a conductor). Furthermore, it is also intended that aspects of a clause can be included in any other independent clause, even if the clause is not directly dependent on the independent clause.

Implementation examples are described in the following numbered clauses:

Clause 1. A method of operating a wireless device, comprising: obtaining data for transmission in a guard interval (GI)-based waveform with a data part and a tail part; obtaining a unique word (UW) sequence for the tail part; and obtaining a suppression signal with filter coefficients configured to suppress leakage from the data part to the tail part; mapping the data, the UW sequence, and the suppression signal to a set of reserved time-domain resources based on a time-domain resource mapping and reservation rule to produce Discrete Fourier Transform (DFT) input data; performing DFT processing on the DFT input data to produce Inverse Fast Fourier Transform (IFFT) input data; performing IFFT processing on the IFFT input data to produce the GI-based waveform with the data part and the tail part; and transmitting the GI-based waveform.

Clause 2. The method of clause 1, wherein the filter coefficients are defined before the mapping, or wherein some or all of the filter coefficients are defined as a function of the mapping.

Clause 3. The method of any of clauses 1 to 2, wherein the tail part corresponds to a zero tail part.

Clause 4. The method of any of clauses 1 to 3, wherein the filter coefficients are predetermined based on the time-domain resource mapping and reservation rule, an oversampling ratio and a starting time-domain resource among the set of time-domain resources.

Clause 5. The method of any of clauses 1 to 4, wherein an initial set of filter coefficients is predetermined based on the time-domain resource mapping and reservation rule and an oversampling ratio, and wherein the filter coefficients are dynamically derived based on the initial set of filter coefficients and a starting time-domain resource among the set of time-domain resources.

Clause 6. The method of any of clauses 1 to 5, further comprising: storing predefined filter coefficients for a first subset of time-domain resources, wherein a second subset of time-domain resources is associated with dynamic derivation of filter coefficients.

Clause 7. The method of any of clauses 1 to 6, further comprising: obtaining a set of candidate filter coefficients; and setting any candidate filter coefficient in the set of candidate filter coefficients that is below a threshold to zero to produce the filter coefficients for the suppression signal.

Clause 8. The method of any of clauses 1 to 7, wherein each filter coefficient of the filter coefficients of the suppression signal is defined based on a set of values associated with a set of adjacent neighbors.

Clause 9. The method of clause 8, wherein each filter coefficient of the filter coefficients of the suppression signal is defined based on an average of the set of values associated with the set of adjacent neighbors.

Clause 10. A wireless device, comprising: a memory; at least one transceiver; and at least one processor communicatively coupled to the memory and the at least one transceiver, the at least one processor configured to: obtain data for transmission in a guard interval (GI)-based waveform with a data part and a tail part; obtain a unique word (UW) sequence for the tail part; and obtain a suppression signal with filter coefficients configured to suppress leakage from the data part to the tail part; map the data, the UW sequence, and the suppression signal to a set of reserved time-domain resources based on a time-domain resource mapping and reservation rule to produce Discrete Fourier Transform (DFT) input data; perform DFT processing on the DFT input data to produce Inverse Fast Fourier Transform (IFFT) input data; perform IFFT processing on the IFFT input data to produce the GI-based waveform with the data part and the tail part; and transmit, via the at least one transceiver, the GI-based waveform.

Clause 11. The wireless device of clause 10, wherein the filter coefficients are defined before the mapping, or wherein some or all of the filter coefficients are defined as a function of the mapping.

Clause 12. The wireless device of any of clauses 10 to 11, wherein the tail part corresponds to a zero tail part.

Clause 13. The wireless device of any of clauses 10 to 12, wherein the filter coefficients are predetermined based on the time-domain resource mapping and reservation rule, an oversampling ratio and a starting time-domain resource among the set of time-domain resources.

Clause 14. The wireless device of any of clauses 10 to 13, wherein an initial set of filter coefficients is predetermined based on the time-domain resource mapping and reservation rule and an oversampling ratio, and wherein the filter coefficients are dynamically derived based on the initial set of filter coefficients and a starting time-domain resource among the set of time-domain resources.

Clause 15. The wireless device of any of clauses 10 to 14, wherein the at least one processor is further configured to: store predefined filter coefficients for a first subset of time-domain resources, wherein a second subset of time-domain resources is associated with dynamic derivation of filter coefficients.

Clause 16. The wireless device of any of clauses 10 to 15, wherein the at least one processor is further configured to: obtain a set of candidate filter coefficients; and set any candidate filter coefficient in the set of candidate filter coefficients that is below a threshold to zero to produce the filter coefficients for the suppression signal.

Clause 17. The wireless device of any of clauses 10 to 16, wherein each filter coefficient of the filter coefficients of the suppression signal is defined based on a set of values associated with a set of adjacent neighbors.

Clause 18. The wireless device of clause 17, wherein each filter coefficient of the filter coefficients of the suppression signal is defined based on an average of the set of values associated with the set of adjacent neighbors.

Clause 19. A wireless device, comprising: means for obtaining data for transmission in a guard interval (GI)-based waveform with a data part and a tail part; means for obtaining a unique word (UW) sequence for the tail part; and means for obtaining a suppression signal with filter coefficients configured to suppress leakage from the data part to the tail part; means for mapping the data, the UW sequence, and the suppression signal to a set of reserved time-domain resources based on a time-domain resource mapping and reservation rule to produce Discrete Fourier Transform (DFT) input data; means for performing DFT processing on the DFT input data to produce Inverse Fast Fourier Transform (IFFT) input data; means for performing IFFT processing on the IFFT input data to produce the GI-based waveform with the data part and the tail part; and means for transmitting the GI-based waveform.

Clause 20. The wireless device of clause 19, wherein the filter coefficients are defined before the mapping, or wherein some or all of the filter coefficients are defined as a function of the mapping.

Clause 21. The wireless device of any of clauses 19 to 20, wherein the tail part corresponds to a zero tail part.

Clause 22. The wireless device of any of clauses 19 to 21, wherein the filter coefficients are predetermined based on the time-domain resource mapping and reservation rule, an oversampling ratio and a starting time-domain resource among the set of time-domain resources.

Clause 23. The wireless device of any of clauses 19 to 22, wherein an initial set of filter coefficients is predetermined based on the time-domain resource mapping and reservation rule and an oversampling ratio, and wherein the filter coefficients are dynamically derived based on the initial set of filter coefficients and a starting time-domain resource among the set of time-domain resources.

Clause 24. The wireless device of any of clauses 19 to 23, further comprising: means for storing predefined filter coefficients for a first subset of time-domain resources, wherein a second subset of time-domain resources is associated with dynamic derivation of filter coefficients.

Clause 25. The wireless device of any of clauses 19 to 24, further comprising: means for obtaining a set of candidate filter coefficients; and means for setting any candidate filter coefficient in the set of candidate filter coefficients that is below a threshold to zero to produce the filter coefficients for the suppression signal.

Clause 26. The wireless device of any of clauses 19 to 25, wherein each filter coefficient of the filter coefficients of the suppression signal is defined based on a set of values associated with a set of adjacent neighbors.

Clause 27. The wireless device of clause 26, wherein each filter coefficient of the filter coefficients of the suppression signal is defined based on an average of the set of values associated with the set of adjacent neighbors.

Clause 28. A non-transitory computer-readable medium storing computer-executable instructions that, when executed by a wireless device, cause the wireless device to: obtain data for transmission in a guard interval (GI)-based waveform with a data part and a tail part; obtain a unique word (UW) sequence for the tail part; and obtain a suppression signal with filter coefficients configured to suppress leakage from the data part to the tail part; map the data, the UW sequence, and the suppression signal to a set of reserved time-domain resources based on a time-domain resource mapping and reservation rule to produce Discrete Fourier Transform (DFT) input data; perform DFT processing on the DFT input data to produce Inverse Fast Fourier Transform (IFFT) input data; perform IFFT processing on the IFFT input data to produce the GI-based waveform with the data part and the tail part; and transmit the GI-based waveform.

Clause 29. The non-transitory computer-readable medium of clause 28, wherein the filter coefficients are defined before the mapping, or wherein some or all of the filter coefficients are defined as a function of the mapping.

Clause 30. The non-transitory computer-readable medium of any of clauses 28 to 29, wherein the tail part corresponds to a zero tail part.

Clause 31. The non-transitory computer-readable medium of any of clauses 28 to 30, wherein the filter coefficients are predetermined based on the time-domain resource mapping and reservation rule, an oversampling ratio and a starting time-domain resource among the set of time-domain resources.

Clause 32. The non-transitory computer-readable medium of any of clauses 28 to 31, wherein an initial set of filter coefficients is predetermined based on the time-domain resource mapping and reservation rule and an oversampling ratio, and wherein the filter coefficients are dynamically derived based on the initial set of filter coefficients and a starting time-domain resource among the set of time-domain resources.

Clause 33. The non-transitory computer-readable medium of any of clauses 28 to 32, further comprising computer-executable instructions that, when executed by the wireless device, cause the wireless device to: store predefined filter coefficients for a first subset of time-domain resources, wherein a second subset of time-domain resources is associated with dynamic derivation of filter coefficients.

Clause 34. The non-transitory computer-readable medium of any of clauses 28 to 33, further comprising computer-executable instructions that, when executed by the wireless device, cause the wireless device to: obtain a set of candidate filter coefficients; and set any candidate filter coefficient in the set of candidate filter coefficients that is below a threshold to zero to produce the filter coefficients for the suppression signal.

Clause 35. The non-transitory computer-readable medium of any of clauses 28 to 34, wherein each filter coefficient of the filter coefficients of the suppression signal is defined based on a set of values associated with a set of adjacent neighbors.

Clause 36. The non-transitory computer-readable medium of clause 35, wherein each filter coefficient of the filter coefficients of the suppression signal is defined based on an average of the set of values associated with the set of adjacent neighbors.

Those of skill in the art will appreciate that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

Further, those of skill in the art will appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the aspects disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure.

The various illustrative logical blocks, modules, and circuits described in connection with the aspects disclosed herein may be implemented or performed with a general purpose processor, a digital signal processor (DSP), an ASIC, a field-programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

The methods, sequences and/or algorithms described in connection with the aspects disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in random access memory (RAM), flash memory, read-only memory (ROM), erasable programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An example storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a user terminal (e.g., UE). In the alternative, the processor and the storage medium may reside as discrete components in a user terminal.

In one or more example aspects, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

While the foregoing disclosure shows illustrative aspects of the disclosure, it should be noted that various changes and modifications could be made herein without departing from the scope of the disclosure as defined by the appended claims. The functions, steps and/or actions of the method claims in accordance with the aspects of the disclosure described herein need not be performed in any particular order. Furthermore, although elements of the disclosure may be described or claimed in the singular, the plural is contemplated unless limitation to the singular is explicitly stated. 

1. A method of operating a wireless device, comprising: obtaining data for transmission in a guard interval (GI)-based waveform with a data part and a tail part; obtaining a unique word (UW) sequence for the tail part; obtaining a suppression signal with filter coefficients configured to suppress leakage from the data part to the tail part; mapping the data, the UW sequence, and the suppression signal to a set of reserved time-domain resources based on a time-domain resource mapping and reservation rule to produce Discrete Fourier Transform (DFT) input data; performing DFT processing on the DFT input data to produce Inverse Fast Fourier Transform (IFFT) input data; performing IFFT processing on the IFFT input data to produce the GI-based waveform with the data part and the tail part; and transmitting the GI-based waveform.
 2. The method of claim 1, wherein the filter coefficients are defined before the mapping, or wherein some or all of the filter coefficients are defined as a function of the mapping.
 3. The method of claim 1, wherein the tail part corresponds to a zero tail part.
 4. The method of claim 1, wherein the filter coefficients are predetermined based on the time-domain resource mapping and reservation rule, an oversampling ratio and a starting time-domain resource among the set of time-domain resources.
 5. The method of claim 1, wherein an initial set of filter coefficients is predetermined based on the time-domain resource mapping and reservation rule and an oversampling ratio, and wherein the filter coefficients are dynamically derived based on the initial set of filter coefficients and a starting time-domain resource among the set of time-domain resources.
 6. The method of claim 1, further comprising: storing predefined filter coefficients for a first subset of time-domain resources, wherein a second subset of time-domain resources is associated with dynamic derivation of filter coefficients.
 7. The method of claim 1, further comprising: obtaining a set of candidate filter coefficients; and setting any candidate filter coefficient in the set of candidate filter coefficients that is below a threshold to zero to produce the filter coefficients for the suppression signal.
 8. The method of claim 1, wherein each filter coefficient of the filter coefficients of the suppression signal is defined based on a set of values associated with a set of adjacent neighbors.
 9. The method of claim 8, wherein each filter coefficient of the filter coefficients of the suppression signal is defined based on an average of the set of values associated with the set of adjacent neighbors.
 10. A wireless device, comprising: a memory; at least one transceiver; and at least one processor communicatively coupled to the memory and the at least one transceiver, the at least one processor configured to: obtain data for transmission in a guard interval (GI)-based waveform with a data part and a tail part; obtain a unique word (UW) sequence for the tail part; and obtain a suppression signal with filter coefficients configured to suppress leakage from the data part to the tail part; map the data, the UW sequence, and the suppression signal to a set of reserved time-domain resources based on a time-domain resource mapping and reservation rule to produce Discrete Fourier Transform (DFT) input data; perform DFT processing on the DFT input data to produce Inverse Fast Fourier Transform (IFFT) input data; perform IFFT processing on the IFFT input data to produce the GI-based waveform with the data part and the tail part; and transmit, via the at least one transceiver, the GI-based waveform.
 11. The wireless device of claim 10, wherein the filter coefficients are defined before the mapping, or wherein some or all of the filter coefficients are defined as a function of the mapping.
 12. The wireless device of claim 10, wherein the tail part corresponds to a zero tail part.
 13. The wireless device of claim 10, wherein the filter coefficients are predetermined based on the time-domain resource mapping and reservation rule, an oversampling ratio and a starting time-domain resource among the set of time-domain resources.
 14. The wireless device of claim 10, wherein an initial set of filter coefficients is predetermined based on the time-domain resource mapping and reservation rule and an oversampling ratio, and wherein the filter coefficients are dynamically derived based on the initial set of filter coefficients and a starting time-domain resource among the set of time-domain resources.
 15. The wireless device of claim 10, wherein the at least one processor is further configured to: store predefined filter coefficients for a first subset of time-domain resources, wherein a second subset of time-domain resources is associated with dynamic derivation of filter coefficients.
 16. The wireless device of claim 10, wherein the at least one processor is further configured to: obtain a set of candidate filter coefficients; and set any candidate filter coefficient in the set of candidate filter coefficients that is below a threshold to zero to produce the filter coefficients for the suppression signal.
 17. The wireless device of claim 10, wherein each filter coefficient of the filter coefficients of the suppression signal is defined based on a set of values associated with a set of adjacent neighbors.
 18. The wireless device of claim 17, wherein each filter coefficient of the filter coefficients of the suppression signal is defined based on an average of the set of values associated with the set of adjacent neighbors.
 19. A wireless device, comprising: means for obtaining data for transmission in a guard interval (GI)-based waveform with a data part and a tail part; means for obtaining a unique word (UW) sequence for the tail part; and means for obtaining a suppression signal with filter coefficients configured to suppress leakage from the data part to the tail part; means for mapping the data, the UW sequence, and the suppression signal to a set of reserved time-domain resources based on a time-domain resource mapping and reservation rule to produce Discrete Fourier Transform (DFT) input data; means for performing DFT processing on the DFT input data to produce Inverse Fast Fourier Transform (IFFT) input data; means for performing IFFT processing on the IFFT input data to produce the GI-based waveform with the data part and the tail part; and means for transmitting the GI-based waveform.
 20. The wireless device of claim 19, wherein the filter coefficients are defined before the mapping, or wherein some or all of the filter coefficients are defined as a function of the mapping.
 21. The wireless device of claim 19, wherein the tail part corresponds to a zero tail part.
 22. The wireless device of claim 19, wherein the filter coefficients are predetermined based on the time-domain resource mapping and reservation rule, an oversampling ratio and a starting time-domain resource among the set of time-domain resources.
 23. The wireless device of claim 19, wherein an initial set of filter coefficients is predetermined based on the time-domain resource mapping and reservation rule and an oversampling ratio, and wherein the filter coefficients are dynamically derived based on the initial set of filter coefficients and a starting time-domain resource among the set of time-domain resources.
 24. The wireless device of claim 19, further comprising: means for storing predefined filter coefficients for a first subset of time-domain resources, wherein a second subset of time-domain resources is associated with dynamic derivation of filter coefficients.
 25. The wireless device of claim 19, further comprising: means for obtaining a set of candidate filter coefficients; and means for setting any candidate filter coefficient in the set of candidate filter coefficients that is below a threshold to zero to produce the filter coefficients for the suppression signal.
 26. The wireless device of claim 19, wherein each filter coefficient of the filter coefficients of the suppression signal is defined based on a set of values associated with a set of adjacent neighbors.
 27. The wireless device of claim 26, wherein each filter coefficient of the filter coefficients of the suppression signal is defined based on an average of the set of values associated with the set of adjacent neighbors.
 28. A non-transitory computer-readable medium storing computer-executable instructions that, when executed by a wireless device, cause the wireless device to: obtain data for transmission in a guard interval (GI)-based waveform with a data part and a tail part; obtain a unique word (UW) sequence for the tail part; and obtain a suppression signal with filter coefficients configured to suppress leakage from the data part to the tail part; map the data, the UW sequence, and the suppression signal to a set of reserved time-domain resources based on a time-domain resource mapping and reservation rule to produce Discrete Fourier Transform (DFT) input data; perform DFT processing on the DFT input data to produce Inverse Fast Fourier Transform (IFFT) input data; perform IFFT processing on the IFFT input data to produce the GI-based waveform with the data part and the tail part; and transmit the GI-based waveform.
 29. The non-transitory computer-readable medium of claim 28, wherein the filter coefficients are defined before the mapping, or wherein some or all of the filter coefficients are defined as a function of the mapping.
 30. The non-transitory computer-readable medium of claim 28, wherein the tail part corresponds to a zero tail part. 